Multi-celled structures are used in a wide variety of applications where light weight and relatively high strength structures are needed to support and/or protect a particular item. One particularly effective structure is the honeycomb which comprises a plurality of nested hexagonal structures. Bees use wax honeycomb to build hives to keep their larvae safe. Aircraft manufacturers use aluminum honeycomb as a core material for aircraft control surfaces. Packagers use kraft paper honeycomb to support and protect products during transportation. The cellular form of honeycomb provides outstanding top-to-bottom compression strength. Besides a high strength to weight ratio, other advantages include resistance to shock, high insulation value, cushioning, and low thermal conductivity factors.
While aluminum honeycomb has been mentioned as used in aerospace applications, another core material has gained considerable popularity in aerospace and commercial applications. NOMEX® honeycomb is a lightweight, high strength, non-metallic honeycomb manufactured with aramid fiber paper. The aramid fiber paper is coated with a heat resistant phenolic resin. NOMEX® honeycomb has a higher shear strength and much higher compressive strength than aluminum honeycomb and is used in aircraft interiors, exteriors and other structural components.
However, several problems with NOMEX® and other honeycomb core materials have been their susceptibility to water, delamination, and impact resistance. Another problem is that strength of the structure is limited by the structure material, for example, a manufacturer may want to use an aluminum honeycomb core but may need additional shear and/or compression strength without adding significant weight to the structure. While honeycomb and other multi-celled structures provide a substantial benefit to various industries, it would be advantageous to provide a multi-celled structure providing additional improvement over current known structures which overcomes one or more of these problems.